This invention relates to a method for stabilizing an aqueous phosphoenolpyruvic acid solution and a container therefor. Phosphoenolpyruvic acid (hereinafter called "PEP") is a compound represented by the following formula: ##STR1## and it is generally expected to be used in the form of sodium salt as the blood preservative and the medicament for activation (Journal of Transfusion Society of Japan, 32, 310 (1986); Japanese patent application No. 127320/1986).
However, PEP is unstable in an aqueous solution and susceptible to hydrolysis. Particularly, as the treatment temperature is higher, this tendency becomes marked during high pressure sterilization in an autoclave.
Therefore, it has been desired to develop a means for stabilizing PEP in an aqueous solution and a container for housing the stabilized PEP accompanied therewith.